Engine.



B.-KR'A 'MER. 4

ENGINE. v

APPLICAUON FILED FEB. 11, I913- 1 ,171,854. v Patented Feb. 15,1916.

v Inventor-p Witnesses: Bernhard Kr''i rne r,

6 1 41% b Hi'soflttokneg UNITED STATES PATENT onnron.

BERNHARD KRAMER, OF CHARIiQTTENBUR-G, GERMANY, ASSIGNOR T GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ENGINE.

Specification of Letters Patent.

Patented Feb. 15, 1916.

Application filed February 11, 1913. Serial No. 747,729.

. is a specification.

The present invention relates to engines and more especially to those ofthe internal combustion type wherein each cylinder is provided with apair of oppositely moving pistons which are connected to angularlydisplaced cranks on the same shaft. Such an engine possesses manyfeatures of advantage in the way of simplicity, but it is diiiicult tobalance them, especially when only one or two cylinders are provided.This is due to the fact that the Weight of metal in the two side rodsconnected to the outer piston is greater than that of the single orcentral rod connected to the other or innerpiston', and to the fact thatthe side rods are longer than said central rod.

I have discovered that such an engine may be effectively balanced byreducing the effective surface of the piston having the long side rodsand increasing the effective surface of the piston having the short rod.The increased area of one over the other will be determined, of course,by the respective weights of said rods and in a measure by the relativelengths of all of, the rods.

In the accompanying drawing is shown in vertical section an engineembodying my invention.

1 indicates a cylinder of any suitable construction having exhaust ports2 and air admitting ports 3, both controlled by the pistons. Thediameter of the upper portion of the cylinder is slightly smaller thanthat of the lower part. Located in the cylinder is an upper or outerpiston 4, and a lower or inner piston 5, the latter being slightlylarger in diameter than the former and hence capable of performing aslightly greater amount of work for a given fuel charge than theupper-piston. The difference in areas will be governed by the excessweight in the side rods of the upper piston over the single rod of thelower piston and in a measure by their respective lengths.

To the upper piston is attached a crosshead 5 moving in guides 6 formedon or secured to the upper end of the cylinder.

On opposite sides of the cross-head are situated pins 7 and these areconnected'by the relatively long side rods 8 to cranks 9 on the mainshaft 10. The lower piston 5 isconnected to the-crank 11 on the mainshaft by the relatively short rod 12. The cranks 9 .and 11 will usuallybe displaced by 180.

- The weights of'the rods of the two pis- -pleted by the differentialareas of thepistons. The difference in areas of the two pistons has beensomewhat exaggerated for the purpose of ilustration.

The invention is inde endentof the number of'pistons connecte and of thekind oi medium acting thereon. It may also be applied to horizontal aswell as vertical cylinders.

In accordance with the provisions of the patent statutes, I havedescribedthe principle of operation of my invention together with theapparatus which I now ;consider to represent the best embodimentthereof; but I desire to have it understood that'the apparatus shown isonly illustrative, and that the invention can be carried out by othermeans.

lVhat I claim as new and desire to secure by Letters Patent of theUnited States, is,-

1. In an engine, the combination of a cylinder, oppositely movingworking pistons mounted therein, the outer piston having a smallereffective area than the inner piston, a main shaft having angularlydisplaced cranks, side rods connecting the smaller piston with two ofthe cranks, and

other of the cranks.

2. In an engine, acombination of a cylwith the shaft 1G shaft, the siderods being partially balanced immm by the central rod and partly by themotive fluid acting on the differential areas of the pistons.

In' witness whereof, Ihave hereunto set my hand this 20th day ofJanuary, 1913.

BERNHARD KRAMER.

Nitnesses HEINRICH DECHAMPS,

T i I HANZ O. (wRAiwN.

